Annotation of secondary metabolite biosynthetic genes in Bacillus thuringiensis genomes

Insecticidal proteins from Bacillus thuringiensis (Bt) have been an important resource for crop protection.  Bt Cry proteins have been used directly for insect control and Bt cry genes have been cloned into crop plants where they confer insect  resistance.  Hundreds of distinct insecticidal Bt Cry, Cyt and Vip proteins have been discovered and evaluated.  The existence of these diverse insecticidal proteins implies that Bt has adapted to exploit insects in the soil and elsewhere.    A related species, Bacillus cereus, has been shown to produce a wide range of natural products, such as peptides, bacteriocins and terpenes, however, only two small molecule insect toxins have been described from Bt:  thuringiensin (b-exotoxin) and zwittermycin (Cry protein potentiating).  Because of its environmental adaptation to exploit insects and apparent lack of small molecules exploitation, we were interested in conducting a thorough evaluation of Bt for potential  to produce other bioactive small molecules.  We took a bioinformatic approach using tools such as AntiSMASH to query 24 publicly available Bt genome sequences for the existence of biosynthetic gene clusters.  Most of these strains contained 8-12 metabolite gene clusters and many cluster types were shared between the strains.  Results of this analysis will be presented along with speculation of the potential for Bt strains to produce novel natural products with importance to agriculture and other fields.